Question: $ { {-5} \times \left[\begin{array}{rrr}{4} & {1} & {-1} \\ {0} & {4} & {4}\end{array}\right] = {?} } $
To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-5}\times{4} & {-5}\times{1} & {-5}\times{-1} \\ {-5}\times{0} & {-5}\times{4} & {-5}\times{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-20} & {-5} & {5} \\ {0} & {-20} & {-20}\end{array}\right]}$